Cuckold fantasy

My girlfriend and I had group sex with 3 girls and 2 guys and are dying to do it again! Lately we've been talking about how hot it would be hearing a guy tell her that he wants and hopes that his cum goes as deep and hard and Tells her that he is getting her pregnant as he is fucking her- she gets wet thinking about an older man (she is 19) saying this as I watch and his wife watches- We almost want her to go out and find a random guy in the bar and let him fuck her and cum in her while i'm in the next room. She wants me to fuck her and tell me that she hopes another man's baby is growing in her and what a cum slut she is. Thoughts?